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A grindstone, also known as grinding stone, is a
Aboriginal grinding grooves, or axe-grinding grooves, have been found across the Australian continent. The working edge of the hatchet or axe was sharpened by rubbing it against an abrasive stone, eventually leading to the creation of a shallow
Grindstone machines work by spinning a circular piece of stone around its center point. These machines usually have pedals for speeding up and slowing down the stone to control the sharpening process. The earliest known representation of a rotary grindstone, operated by a crank handle, is found in the Carolingian manuscript known as the
A grindstone, also known as grinding stone, is a sharpening stone
Sharpening stones, or whetstones, are used to sharpen the edges of steel tools such as knives through grinding and honing.
Such stones come in a wide range of shapes, sizes, and material compositions. They may be flat, for working flat edg ...
used for grinding
Grind is the cross-sectional shape of a blade.
Grind, grinds, or grinding may also refer to:
Grinding action
* Grinding (abrasive cutting), a method of crafting
* Grinding (dance), suggestive club dancing
* Grinding (video gaming), repetitive and ...
or sharpening ferrous
In chemistry, the adjective Ferrous indicates a compound that contains iron(II), meaning iron in its +2 oxidation state, possibly as the divalent cation Fe2+. It is opposed to " ferric" or iron(III), meaning iron in its +3 oxidation state, suc ...
tools, used since ancient times. Tools are sharpened by the stone's abrasive qualities that remove material from the tool through friction in order to create a fine edge. Similar to sandpaper
upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)).
Sandpaper and glasspaper are names used for a type of coated abrasive that consists of sheets of paper or cloth with abrasive material glued to ...
, each stone has a different grit that will result in sharper or duller tools. In Australia, Aboriginal peoples
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
created grinding grooves by repeated shaping of stone axes against outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
Features
Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficia ...
s of sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates ...
.
History and description
Grindstones have been used since ancient times, to sharpen tools made of metal. They are usually made fromsandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates ...
.
Grinding grooves
Aboriginal grinding grooves, or axe-grinding grooves, have been found across the Australian continent. The working edge of the hatchet or axe was sharpened by rubbing it against an abrasive stone, eventually leading to the creation of a shallow oval
An oval () is a closed curve in a plane which resembles the outline of an egg. The term is not very specific, but in some areas (projective geometry, technical drawing, etc.) it is given a more precise definition, which may include either one ...
-shaped groove over time, The grooves vary in length from up to , and can be up to wide and deep. They are often found near water, which was sprinkled on the stone during grinding to reduce dust.
Machines
Grindstone machines work by spinning a circular piece of stone around its center point. These machines usually have pedals for speeding up and slowing down the stone to control the sharpening process. The earliest known representation of a rotary grindstone, operated by a crank handle, is found in the Carolingian manuscript known as the Utrecht Psalter
The Utrecht Psalter (Utrecht, Universiteitsbibliotheek, MS Bibl. Rhenotraiectinae I Nr 32.) is a ninth-century illuminated psalter which is a key masterpiece of Carolingian art; it is probably the most valuable manuscript in the Netherlands. It ...
. This pen drawing from about 830 goes back to a late antique original. The Luttrell Psalter
The Luttrell Psalter (British Library, Add MS 42130) is an illuminated psalter commissioned by Sir Geoffrey Luttrell (1276–1345), lord of the manor of Irnham in Lincolnshire, written and illustrated on parchment ''circa'' 1320–1340 in Engla ...
, dating to around 1340, describes a grindstone rotated by two cranks, one at each end of its axle. Around 1480, the early medieval rotary grindstone was improved with a treadle and crank mechanism.
See also
* Lathe * Millstone * Punch (tool) *Grindstone City Historic District
Grindstone City Historic District is an industrial historic district located on M-25 in Grindstone City, Michigan. It was listed on the National Register of Historic Places in 1971.
History
Captain Aaron G. Peer was born in Dundas, Ontario, in 1 ...
References
Sources
* * Woodworking Grinding and lapping Knives {{metalworking-stub